Automatic expansion valve



June 30, 1925. 1,544,194

B. c. STEWART ET AL AUTOMATIC EXPANSION VALVE Filed Dec. 16, 1918.

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Patented June 30, 1925.

UNITED STATES PATENT OFFICE.

nunT c. STEWART, or BIRMINGHAM, AND CLARENCE M. IIoLEEY, or DETROIT, moni- GAR, ASSIGNORS, IBY IIEsNE ASSIGNMENTS, To THE noovEn. COMPANY, or NonTn CANTON, omo, a CORPORATION or 0x10.

AUTOMATIC EXPANSION VALVE.

Application filed December 16, 1918. Serial No. 288,848.

To all whom it. may concern:

Be it known that we, BURT G. STEWART and CLARENCE M. HOLLEY, citizens of the United States, residing at, respectively, Birmingham and Detroit, counties of Oak: land and Wayne, State of- Michigan, have invented a certain new and useful Improvement in Automatic Expansion Valves, and declare the following to be a full, clear, and exact description of the same, such as Wlll enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to automatic expansion valves for artifical refrigerating systems and other systems forcirculation of a fluid having a high and a low pressure side, and its object is to provide a valve automatic in operation and under influence of a pump adapted to produce a two-stage expansion of the circulating fluid 1n passing therethrough. A further object of the 1nvention is to provide a valve of such construction that a small volume only, in comparison to the volume of the expansion system, is expanded at any interval, the

valve operating to first discharge a small volume of liquid under pressure to the vacuum side of the valve to relieve the vacuum in the small chamber on that side and then discharge this partially expanded volume into the expansion coils where the final expansion takes place.

With the ordinary automatic expansion valve between the high and low pressure sides of the circulating system heretofore used, when the valve opened, it remained open until the vacuum on the expansion side of the system was relieved to an extent to permit the closing of the valve. By such previous and known arrangement a considerable period of time is involved in reducing the vacuum in the expansion coils to an extent to permit closing of the valve and thereafter a considerable period of time was required to relieve the vacuum suificient at least to produce the desired reduction in temperature of the storage chamber resulting 1n fluctuations in the temperature. With the apparatus herein described the principal object is to (prevent this fluctuation n temperature an in the vacuum maintained in the expansion coils and to provide an exansion valve automatic in operation wherey a substantially constant vacuum is maintained in the expansion coils.

A further ob ect of the invention is accomplished by the two-stage expansion mentioned in the performance of which a small chamber on the vacuum side of the valve is first relieved by a discharge from the pressure side and then the chamber opened to the expension coils, the object being to reduce the tendency of foreign matter, such as oil for instance in the circulating medium, from, congealing at the point of expansion as is hereinafter more fully described. A further object of the invention is a valve having the general characteristics stated that is adjustable in a pressure line and thus preventing a relatively great reduction of temperature at this point and assisting in the prevention of congealing of foreign matter and consequent freezing of the valve. These several objects and novel features of the invention are hereinafter more fully described and claimed, and the preferred form of the invention is shown in the accompanying drawing which is a vertical section of a valve embodying my invention.

' In the construction shown, the device consists of a lower preferably cylindrical member l and a cap member 2 therefor each of such complemental shape as to provide a chamber therebetween. To the cap member 2 is secured a hollow stem 3 to which is to be connected the high pressure line of acirculating system, and the member 1 at the bottom is provided with a threaded inlet 4 to which is to be attached the iping forming part of the low pressure si e of the system. The tubular member 3 is provided with a channeled extension5 which extends copper. The upper end of this cylinder is secured by soldering the same to a shoulder formed at the u per end of the part 5 and the lower end 0 the cylinder is secured to a hub 6" of a plate 7 as shown. This plate 1s preferablycylindrical in form and to the periphery thereof is secured a second and more deeply corrugated cylinder 8, the upper end of which is secured to a ring 9 0 of greater diameter than the cylinder. Th1s ring is secured between the abuttin portions of the parts 1 and 2 forming a gas et therefor. The cylinder 6 is much longer than the cylinder 8 but, the corrugations being more numerous in the part 6 and less in depth, the two members 6 and 8 practically expand or contract to an equal extent. The lower end of the part 5 extendsinto the apertured hub of the plate 7 but 15 spaced from the wall thereof as indicated.

- This plate is provided also with an external hub 9 threaded to receive the threaded body of a coned valve 10. This valve is provided with a lock nut .11 and when the parts 6 and 8 and tube 3 have been assembled on the part 2 of the casing, the valve is set to cause expansion to a'greater or less degree n of the corrugated cylinders whereby the natural tendency-of the cylinders to'contract tends to hold the valve closed, and it is to be understood that the area of the channel in the part 5 is so small that the pressure exerted on the face of the valve open to the pressure line is insuflicient to expand the cylinders 6 and 8 and open the valve to flow therethrough. By the construction described, there is a small chamber 12 provided inside the cylinder 6 and between the c linder and the tubular member 5, and this chamber is open to the chamber 14 formed between the plate 7 and cylinder 8, and the case 1 by means of the apertures 13 formed in the hub member 9. This chamber 14 is thus open at all times to the chamber 12-v thus discharged into the vacuum coils and,

and forms the first expansion chamber of the system. It is to be noted in passing, that' to be assembled and the valve to be set while the two parts are disengaged, and that in securing the parts together by means of the bolts 15, the ring 90 provides a gasket and prevents any leakage through the interstice between the meeting surfaces of the two parts whereby the vacuum in the chamber 14 might be broken. This construction allows the several parts to be readily assembled or disassembled. The valve body has a-valve 10 at one end and a valve 16 at the opposite end which extends downward through the threaded stem 4. A seat for the valve 16 is provided in the threaded plfig 17 in the stem 4. This plug has a central channel 18 therethrough adapted to be'closed by the valve 16, and the plug 17 may be varied in position relative to the valve 16 by turning the same in the threaded stem and thus provide for a greater or less movementof both the valves 10 and 16. "The threads in the stem and plug should be fine. in character in order that a minute adjustment of the plug may be secured and, by such adjustment, the degree of vacuum to be maintained in the expansion system may be varied. After the plug is once set, however, and the system connected up, it is evident, by reason of the plug being on the interior of the piping, that it is impossible to disarrange the valve from the exterior and thus the disarrangement by unauthorized persons is prevented as is desirable in systems in general public use.

The operation of the device is as follows:

It being understood that a pump ordinarily used with a system of this character is utilized to compress the fluid on the pressure side of the system and to draw the fluid from the vacuum side. With the pump in operation in a system of this character involving the valve described, a vacuum is produced on the vacuum side of the system 'pressure line into the chamber 14 and relieve the degree of vacuum therein to an extent to allow the natural contraction of the cylinders 6 and 8 to again close the valve 10. The closing of the valve 10 opens the chamber 14 to the vacuum side of the system, and the fluid in the chamber 14 is by reason of its small volume in comparison to the capacity of the coils, is immediately expanded to its greatest extent. By this arrangement also and due to the fact that the chamber 14 is "small in volume in comparison to the volume of the expansion side of the system. the degree of vacuum therein is not relieved by this discharge and thus, although there is practically continual discharge of fluid from the high pressure to the low pressure side of the system, it is at no instant of time of such volume as to cause materially evident fluctuation in the degree of vacuum maintained. F urthermore, there is not a gradual expansion of fluid when discharged from the chamber but in fact the expansion is almost instantaneous, and therefore is highly eflicient as it is instantly in condition to take up heat. The principal object of the invention is inl volved inthis feature of construction by means of which a small quantity of fluid under pressure is first discharged into a chamber to relieve the vacuum therein which closes the pressure side of the system and opens the chamber to the expansion side, and this operation in practice is found to be very rapid, the valve fluctuating so rapidly as to cause a continuous sound.

The chamber formed between the exterior of the cylinder 6 and interior of the cylinder 8 and case 2 as before stated, is open to atmosphere through the port 19. By this arrangement air at normal temperature may enter the chamber 20 and maintain the temperature of the walls of the cylinders and plate 7, and consequently the valve 10 at such degree as'to prevent congealing of any foreign substance, as oil or other matter, at the point of discharge into the chamber 14. Thus, freezing of the valve on its seat is prevented. It is furthermore necessary to open this outside of the cylinder 6 and inside of the cylinder 8 to atmosphere in order that the pressure thereof may be utilized to open the valve upon suflicient reduction in pressure in the chamber. Further, by opening the outside of the cylinder to atmosphere no material temperature change takes place in the air outside the cylinder.

From the foregoing description, it is evident that the valve is simple and inexpensive in construction, and that, by means of the two-stage expansion described, high efliciency in operation is attained, and further that the construction is of such character that when once set to produce a certain effeet will continually operate in the predetermined manner.

Having thus fully described our invention, what we claim is'- 1. An automatic expansion valve comprising in combination with the high and low pressure lines of an artificial refrigerating system, a valve member, an expansible member normally holding the valve to close the high pressure line, a chamber, one side of which is formed by the expansible member and into which both the high and low pres sure lines lead, a second valve controlling the low pressure line connected with the expansible member opened by movement of the member to close the high pressure line and closed by expansion of the member to open the high pressure line.

2. An automatic expansion valve comprising in combination with the high and low pressure lines of an artificial refrigerating system, a chambered body, an expansible member therewithin dividing the body into two compartments, one open to atmosphere and the other closed to atmosphere, a valve member connected with the expansible member, both the high and low pressure lines leading into the closed chamber, and the valve normally closing the high pressure adapted to be expanded by pressure, a casing connected therewith to,form a chamber closed to atmosphere into which both the high and low pressure lines lead, a valvenormally closing the high pressure line and opening the low pressure line to the chamber, reduction inpressure in the chamber causing the member to expand to open the high pressure line and close the low pressure line toirelieve the vacuum in the chamber and allow the expansible member to contract to close the high pressure line and open the low pressure line.

4. An automatic expansion valve comprising in combination with high and low pressure lines of an'artificial refrigerating system, a hollow valve body, a corrugated cylinder therein capable of expanding and contracting and forming with said body a chamber closed to atmosphere, the outer wall of the corrugated body being open to atmos phere and the high and low pressure lines both leading into the closed chamber, a valve carriedby the cylinder, the cylinder being partlally expanded by the seating'of the valve in the high pressure line, the construction being such that the seating of the valve in the high pressure line opens the low pressure line to the chamber and reduction in pressure in the chamber causing the cylinder to expand by atmospheric pressure to open the high'pressure line and close the low pressure line.

5. An automatic expansion valve for use between the high and low pressure lines of an artificial refrigerating system comprising the combination with said lines, of a chamber into which both lines open in adjacent aligned relation, a flexible member forming a wall of the said chamber open to atmosphere on the exterior, a double valve member carried by the flexible member adapted to seat respectively in the terminals of the high and low pressure lines, the valve member being adjustable and adapted to close the high pressure line by a tension of the flexible member, the seat for the valve in the low pressure line being adjustable to vary the extent of movement of the valve to Teat therein'on opening of the high pressure 6. A device for maintaining a practically constant pressure in the low pressure side of a fluid circulating system having a high and a low pressure line, comprising the combination with said lines, of a chamber into which both lines lead, a valve member for alternately closing and opening both the said lines, the valve normally closing the high pressure line, means operated by influence of a decrease in pressure in the chamber below the normal pressure of the low pressure line adapted to actuate the valve to open the high pressure line and close the low pressure thin metal allowing the chamber to be expanded o r contracted longitudinally, a plate closing one end of the cylinder, the valve being supported by the plate and the plate and cylinder forming one wall of the chamber, said valve being adjustable longitudinally of the cylinder to seat in the outlet of the high pressure line under pressure producing a partial expansion of the cylinder wall and predetermining the extent of decrease in pressure in ,the chamber required to expand the cylinder and'open the chamber to the high pressure line and close it to the low pressure line.

8. An expansion valve for use between high and low pressure lines of fluid-circulating systems and the like consisting of a two-part casing providing a chamber, the parts being adapted to be connected in a manner to eificiently seal the same to atmosphere, a tubular member extending downward from the upper art of the said casing 'exteriorly thereof to e connected with the high pressure line, a tubular extension on the other part of the casing adapted to be connected with the low pressure line, a corrugated cylindrical member about the said tubular member and secured thereto to seal the end of the cylinder, a second cylindrical member of corrugated walls surrounding the first member, a plate between the two members and secured thereto, the plate having an opening in the center communicating with the interior of the smaller cylinder,

' the lower part of the case surrounding the outer cylinder and plate and providing a chamber between the casing and said outer cylinder plate and inner cylinder sealed to atmosphere, a valve carried by the plate closing the high pressure line, the valve being adjustable to produce a tension of the cylinder walls to hold the valve closed at a predetermined degree of pressure, a second valve in fixed relation with the first valve adapted to open the low pressure line on closing the high pressure line and vice versa.

9. The combination with the high and low pressure lines of a fluid circulating system, of a valve structure between the said lines comprising a chambered body into which both lines open, a valve therein movable to close and open the high and the low pressure line alternately, and means for actuating the valve controlled by variation in the pressure in the chamber.

10. An automatic expansion valve for use between high and low pressure lines comprising a body having a chamber into which both lines open at different points, a valve member in a chamber movable between the said openings to alternately open and close the same,oa member controlled by pressure in the said chamber to move the valve, and means for varying the degree of pressure required to operate the said member.

11. An automatic expansion valve for use between high and low pressure lines of a fluid circulating system comprising a body provided with a chamber into which the said lines open in alignment on opposite sides of the chamber, a valve in the said chamber movable to close and open the lines in alternate relation, an expansible member connected with the valve and subject to pressure of the chamber and so arranged that certain increase in pressure moves the valve to close the high pressure line and open the low pressure line and certain reduction in the pressure moves the valve to close the low pressure line and open the high pressure line.

12. An automatic expansion valve for use between high and low pressure lines of a fluid circulating system comprising a body member having a chamber in the upper side of which the high pressure line opens and in thelower side of which the low pressure line opens, said openings being in 'vertical alignment, a valve movable between the said opening to close the one and open the other in alternate relation, and a member under tension with which the valve is connected and subject to the pressure of the fluid in the chamber for causing movement of the valve. v

13. An automatic expansion valve comprising the combination of the high and low pressure lines of an artificial refrigerating system, a valve member between the said lines, the valve member being provided with a chamber into which both the high and low pressure lines open at different points, a valve movable between the opening of the saidlines to cl'ose'the one and open the other alternately, means controlled by pressure in the chamber for moving the valve, and means for varying the pressure pressure control means is opnected with said member, saidvalvebeing movable by said member to close the opening of the high pressure line upon certain high pressure in the chamber and simultaneously open the low pressure line to the chamber and movable upon certain reduction in pressure to close the opening of'the low pressureline and open that of the high pressure line to the chamber, and means for, predetermining "pressures at which the said valve controlling member is 0 rable.

15. The combination with a flui circulating system having ahigh and a low pressure side, of means for maintaining a substantially constant predetermined low pressure in the said low pressure line comprising a valve body having a chamber into which both lines open, a valve therein movable to open and close the said lines to the chamber alternately, a control device for the valve subject to the pressure in the chamber and movable to actuate the valve by variation in pressure therein, and a tension member adjustable to determine the pressure at which the valve shall close the high pressure line and open the low pressure line and open the high pressure line and close the low pressure line. 1

16. The combination with a fluid circulating system having a high and a low pressure line, of automatic means for controlling flow from the high to the low pressure line including a body having a chamber, a valve therein, means connected therewith responsive to certain pressure in the high pressure line to close the said high pressure line to the chamber and open the low pressure line thereto and further responsive to certain low pressure to close the low pressure line to the .chamber and open the high pressure line thereto, and means for causin said responsive means to respond to var1ous high and low pressures.

17. An automatic expansion valve for use between high and low pressure lines com rising a body having a chamber into which both lmes open, means in' the chamber operable to practically simultaneously open one line and close the other in alternate relation, and a control device responsive to predetermined pressure in the chamber produced by the line open to the chamber to actuate the said means.

18. An expansion valve connecting a hi h and a low pressure line, a chamber in t e valve, means controlling admission from the high pressure line to the chamber, said means pressure actuated, and a restricted port comprising the outlet from the valve to the low pressure line.

19. In a valve for expanding a liquid refrigerant, a chamber formed In the valve, pressure actuated means admitting liquid to the valve chamber, evaporation of which within the valve operates the pressure actu .pansion occurs in the chamber.

ated means to close the liquid admission means, the gas outlet from the valve'being of restricted size to dprevent free passage of the volatilized liqui whereby a primary ex- 20. *An expansion valve connecting a high to a low pressure line and com rising a cas ing enclos ng a chamber, the igh and low pressure lines opening into the casing, a flexible member and means associated therewith controlling bymovement thereof the opening of--theuhigh pressure lines of the chamber, the flexible member biased to maintain the chamber closed to the high pressure line, the low pressure connection to the chamber being of restricted area, all whereby a deficiency of pressure in the low pressure line will cause movement of the flexible member, thereby opening the high pressure connection to the chamber for admission and primar expansion of a quantity of volatile flui the expansion of which,.because of the restricted low pressure connection, will build up a pressure in the chamber acting on the flexible member to close the high pressure inlet opening.

21. In an expansion valve, having a high and a low pressure line connection, a chamber to'which a limited quantity of liquid refrigerant is introduced from the hi h pressure line and initially expanded, and means" openin the chamber to the low pressure line after t e initial expansion of the refrigerant in the chamber.

22. In an expansion valve, for a refrigeration system, having high and low pressure lines, a chamber to which a limited quantity of high pressure refri erant is admitted, means sea ing the cham r against further admission, of high pressure refrigerant whereby partialexpansio'n may occur, and

means admittin the partially expanded refrigerant to the ow pressure line.

23. Inan expansion valve, for a refrigera- A expansion, the means comprising a chamber having a flexible member therein, given motion by the initial expansion of the refrigerant to operate means preventing further admission of high pressure refrigerant and to operate means admitting the initially expanded refrigerant to the low pressure line.

25. An expansion valve having a chamber therein, provided with an inlet and an outlet, the inlet being of restricted size, means admitting a. hmlted quantity of volatile fluid the chamber for volatilization and initial expansion, and means discharging the partially volatilized fluid.

26. An expansion valve having a chamber therein, provided with an inlet and an outlet, the inlet being of restricted size, means admitting a limited quantity of volatile fluid to the chamber for volatilization and initial expansion, and means discharging the partiall; volatilized fluid, the first means c0mprising a flexible wall of the chamber, and a valve, movement of the flexible Wall operating the valve, the second means comprising a valve operated by movement of said flexible wall.

27. A valve for the expansion of a volatile fluid comprising means admitting to the valve a limited quantity of the fluid for vaporization and initial expansion, the initial expansion operating means allowing discharge and final expansion of the vaporized initially expanded fluid.

In testimony whereof, we sig this specification.

BURT C. STEWART. CLARENCE M. HOLLEY. 

